Study Of Information Hiding Techniques Based On Text

With dramatic advance of Internet and wide application of the multimedia technology, information-hiding techniques have become a new hot topic in the domain of the information security. Today's information hiding techniques mainly use image, audio and video as cover objects; techniques using text as cover object are relatively fewer because of its speciality. But in fact, lots of people's originality can be saved and transferred by the way of text. As an important way of information transfers, the application fields of text exceed consumedly image, video, audio, etc. In addition, text watermarking has an important effect on official business and electronic commerce during the Internet age. We believe, with reason, that the information hiding techniques based on text have a potential value. Since this, the text hiding techniques are discussed in detail in this paper. In the thesis, firstly we introduce the basic concepts and theoretics of information hiding technologies and digital watermarking, such as characteristics, classification and application and so on. Then we analyze the information hiding techniques based on text in detail; give a survey of today's popular algorithms of text document information hiding and their advantages and shortcomings, besides we implement some of them. Whereafter, we expound the specialty of text watermarking compared to text information hiding, and present two kinds of text watermarking algorithms which are based on text document image and natural language processing. On the basis of analyzing some algorithms before-mentioned, we propose two new methods. The first one is literal color information hiding technology, which can hide more information. Subsequently,we propose a new text document information hiding algorithm in terms of word classification and segment classification, which hides information by using a scenario of integrating various of methods, such as transform of fonts, text color, and so on. It is robust to a certain extent, but only can hide a little information, so we give another improvement of it which can hide more information. After implementing these methods, we analyze the experimental results of them and give a conclusion.